Manually operated sheet metal flanging tool



H. L. FARNSTROM Jan. 13, 1948.

MANUALLY OPERATED SHEET METAL FLANGING TOOL Filed March 50, 1945 2 Sheets-Sheet l INVENTOR.

Jan. 13, 1948. H. 1 FARNSTROM MANUALLY OPERATED SHEET METAL FLANGING TOOL Filed March 50, 1945 2 Sheets-Sheet 2 INVENTOR.

Patented Jan. 13, 1948 UNITED STATES ATENT ori-ICE MANUALLY GPERATED SHEET METAL FLANGING TL Harry L. Farnstrom, Erie, Pa.

Application March30, 1945, Serial No. 585,700..

4 Claims.

The object of my present invention is to provide a tool for turning flanges on the edges of sheet material, more particularly on the edges VAof thin metal sheets such as those use-d in forming the so-called skin or surface covers of airplane bodies or fuselages, or those of other` vehicle of the iiange can be obtained and maintained constant, thus enabling flanges of different degrees of angularity and of different widths to be turned on different sheets, with the same tool.

To these and other ends my invention consists in further improvements and arrangement of parts all as will be set forth in the following specication, the novel features thereof being pointed i out in the appended claims.

In the drawings:

Fig. l is a side elevation of a flanging tool representing one embodiment of my invention.4

Fig. 2 is a top plan view thereof, the sheet guide mechanism being shown retracted in full lines in a position to guide the tool within a concave curve or the inside of a circle, and in dotted ylines in an advanced position for operation on a convex curve.

Fig. 3 is an end elevation of the tool.

Fig. 4 is an enlarged diagrammatic View showing a side elevation of the anging rolls, and the automatic positioning of the tool with reference to the sheet during the turning of a ange.

Fig. 5 is a vertical sectional View taken on the line 5oz-51: of Fig. 2 showing the manner of mounting the guide members.

Fig. 6 is a side elevation showing a modification of the tool in a simplied form for flanging sheets having straight edges or edges of only slight curva-r tures.

Fig. 7 is a bottom plan view of one of the 'ad-- justable guide arms.

Fig. 8 is a side elevation showing in detail the center guide member carried on the arm ,illus-,f

trated in Fig. 7.

Similar reference numerals in the several ngures indicate similar or the same parts.

In carrying out my invention, I am primarily concerned in furnishing a tool of convenient size, weight and construction that may be manipulated 2 in the hand of an operator, the onlyrskill required r being the ability toA hold the tool against the guideV furnished by the sheet itself and advance it in this position from one end of the sheet to the other. To these ends the tool comprises a body l,

a movable member or frame p-iece 2 thereon, and a pair of complementary anging rolls 3 and ii, one of which is carried on eachvof said parts,A and which in operation lie upon the opposite sides or faces of a sheet to be flanged.

On its front side the body and frame piece are faced ofi in a common plane to form a backing for the rolls. If desired, this face on one ofthe parts may be extended across the meeting pointsV of the rolls and at each sidethereof to form'a `guide for the edge of a sheet to be anged which will work Very well on sheets having straight` edges. (See Fig. 6.) However, because of this limitation, I prefer to provide adjustable guides whichY will enable the tool to be used with equal facility on sheets having either concaved or convex j shaped edges, as will be later described, thusgiving it universal applicability. The rear or off side, of the body is provided with a handle 5 by which' it is manipulated. The grip portion of thehandle' is located in the plane of the sheet beingoperated upon, i. e. it lies substantiallyopposite the meeting or working points of the rolls 3 and ll. The adjustable bearing points are located atopposite sides of the meeting point of the rolls which are 4 movable into positions ahead of or behind they plane of the anging rolls to position the rolls on the sheet by reference to its edge.

An examination of Fig. 2 shows the body and 'frame piece on their front sides extending angularly at each end away from the rear faces ofV the crimping rolls.' The portions of the bodyV and n frame which form the `backings of the rolls l3 and; 4 and carry their journal studs Sci-la are also separated as shown in Figs. 1 and 3 to provi-de a space between them. Within this space, I locate the adjustable bearing points which are shown in detail in Figs. 2 and 5.

Extending rearwardly on the body I is a bracket 1 Il! carrying a stud Il on which are pivoted the by extending rearwardly of their pivot point iingers I2a-I3a which have inclined faces with which engages the beveled head of a screw I6 which is tapped into the bracket I. In this assembly of the parts a turning of screw I6 in a direction to cause the advance serves to throw the extremities of the arms I2 and I3 outwardly in a direction forward of the plane of the working portion of the flanging rolls 3 and 4 and by retracting the screw I6 these arms are freed and may be pushed rearwardly of said plane, these two positions thus accommodating the instrument to follow either the convex or concave edges of a sheet edge having sharp curvatures. In operatlng on sheets with straight edges, or those of very slight curvatures, only slight initial adjustment of the screw I6 is required to position the leading guide roll I and the trailing guide roller I with respect to the depth or width of the flange to be turned.

The second member of the tool body, namely the relatively adjustable frame piece 2, may conveniently be made in the form of a lever arm having at one end a tongue 2a pivoted at 2b between the ears on an upwardly rearing arm Ia. on the body. Its forward face lies in the plane of the guide face of the body and its free end extends between a coil spring 2c, which serves to move it away from the body, and a thumb nut 2 I threaded on a pivoted bolt 22 attached to the body and serving to move the arm in the opposite direction. The desired position of the lever in which it is set with respect to the body is maintained by a friction spring or latch 23 which engages the knurling on the edge of the nut 2I.

The complementary flanging rolls 3 and 4 are mounted in vertical alinement on the parts I and 2, their respective journals being preferably ball races carried on the studs 3cr-4a the inner ends of which are threaded into the body I and frame piece 2. One of these rolls, preferably the upper one, is provided on its inner edge with an annular beveled projecting rim 24, the other roll being correspondingly undercut as indicated at 25. The angularity of said rim and undercut with respect to the faces of their respective rolls may be varied but in practice I have found that a 45 angle is well adapted to accommodate the tool to universal service.

The adjustable member 2 is set by the nut 2l to permit the entrance of the sheet to be flanged between the plane faces of the two rolls. If a severe flange is to be turned on the edge of the rolls this adjustment is only equal to the thickness of the sheet so that the entering corner of the sheet is deflected angularly the full equivalent of the angles of the rim and undercut of the rolls. However as this extreme degree of angularity of the flange is generally not required and more often the deflection desired lies between and 20, this deflection is obtained by separating the rolls a distance greater than the thickness of the sheet so that the periphery of the rim 24, with reference to the sheet thickness and the shoulder of the undercut 25 will produce the desired deflection or set in the edge of the sheet. In any position of the anging rolls the operation of the machine is guided by the edge of the sheet, the deflection of the flange being determined by the distance between the shoulders on the two rolls. And the width or depth of the ange is governed by the distance the sheet is allowed to project into or through and beyond the rolls by the adjustment of the screw I6 in the first instance and which controls the posi- 4 tion of the arms I2 and I3 on their pivotal point A noticeable feature of this arrangement of parts is that once the guides are set for width and the frame pieces adjusted for flange deflection they cooperate to assure the operator bringing the tool into engagement with the edge of a sheet in the rst instance, tilting it at the proper angle (see Fig. 4) automatically at the beginning of a flanging operation and holding it against said sheet in this position throughout the length of the flange to be formed.

While it is not necessary on all kinds of flanging work and especially when the tool is operated by one of experience, I prefer to provide a third guide 38 located between the guides I4 and I5 at approximately the center of the tool. It is located slightly ahead of the working point of the Hanging rolls and constitutes a lead-in guide which assures the starting edge of the sheet entering between the rolls the propel` distance to assure the flange to be of the proper width. The guide 30 has a rounded face on the forward edge of the upstanding end of an arm 3| which is carried in a diagonal slot 3Ia on the underside of the arm I3 with reference to which it may be advanced or retracted by a screw 32. The latter is carried on an upwardly extending projection 33 and its inner end engages a threaded aperture in the rear side of the arm I3. This adjustment, it will be seen, accurately positions the center guide 3i) in relation to the guides I4 and I5 for anging sheets with either straight or curved edges.

In the modification of the tool shown in Fig. 6 I have shown the two body members I' and 2' on which the adjustable guides are omitted and a single guiding surface provided, as indicated at 33. This is accomplished by making the face of one of the two body members, preferably the part I', adjacent the flanging rolls so that it overlaps their meeting point and extends in a straight line at opposite sides thereof. The face 33 may be continuous, or otherwise formed, it being sufcient if it provides three bearing points for engaging the edge of a sheet, one at approximately the center, the others lying in spaced relation and at opposite sides thereof.

Tools made in accordance with my invention are particularly serviceable in working on thin metal sheets having large areas as these may be fianged on a work bench after they have been cut to the required pattern shape.

I claim as my invention:

1. In a manually Operated sheet flanging tool the combination with a body member, a lever arm pivoted thereto at one end and means for adjusting its free end relatively to the body, said body and lever being each faced at their forward side in a common plane, of a pair of cooperating anging rolls, mounted on axes normal to said common plane, one to said lever and the other to said body and one above the other with their working points between the body member and the lever arm, arms pivoted on the body member beyond the rear faces of the rolls and having their extremities extending at opposite sides of said working points of the rolls and forming guides for positioning the edge of a sheet to be anged, bell crank extensions on said guide arms projecting rearwardly from their pivot, and an adjusting member cooperating with said bell cranks for moving the free ends of the guide arms laterally to the plane of rotation of the rolls.

V2. In a sheet flanging tool the combination with a frame composed of two body members spaced apart and relatively adjustable, and complementary anging rolls carried on said members, of jointed arms located between said members mounted on one of them for simultaneous movement, their extremities forming guides at each side of the working point of said rolls for a sheet to be anged, and means for simultaneously moving said arms to adjust their guide extremities in the axial direction of said rolls.

3. In a sheet flanging tool the combination with a body member and an overlying member spaced therefrom and movable relatively thereto, and cooperating flanging rolls carried on said member, of guide arms pivoted on the body, their outer extremities forming guides for the edge of a sheet and lying at opposite sides of the working points of said rolls, and an adjusting device common to the two arms for moving their guiding extremities independently of the movement of said body to regulate the position of a sheet to be anged between the flanging rolls.

4. In a manually operated sheet flanging tool the combination with two relatively movable body REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 1,802,232 Birdwell et al Apr. 21, 1931 2,024,803 Nelson Dec. 17, 1935 886,214 Houck Apr. 28, 1908 337,427 Noyes Mar. 9, 1886 2,146,949 Flagler Feb. 14, 1939 22,459 Stow Dec. 28, 1858 648,156 Steward Apr. 24, 1900 

